Senate talks aimed at getting broad support for requiring background checks at more gun sales have ground to a halt, but a bill that would strengthen laws against gun trafficking appears to be gaining momentum in Congress.

The Senate version of the trafficking legislation announced Monday by Judiciary Committee Chairman Patrick Leahy, D-Vt., would make it a federal crime to purchase a firearm for a person who is barred from owning one – a "straw purchase" — and would punish sellers who sell a gun despite having a "'reasonable cause to believe" it will be used in a criminal act.

Sen. Mark Kirk, R-Ill., and Sen. Susan Collins, R-Maine, have endorsed the bill, and gun rights advocates in Congress have generally not raised the same concerns about the trafficking bill that they have about other efforts to create tougher gun regulations.

The trafficking bill is one of four gun bills that the Senate Judiciary Committee is scheduled to begin considering Thursday.

Senators had been trying before Thursday's vote to get a deal on a background check bill, but that effort fell apart this week.

Negotiations between Kirk and Sen. Tom Coburn, R-Okla., and Sens. Charles Schumer, D-N.Y., and Joe Manchin, D-W.Va., stalled after weeks of talks, according to a Schumer aide who is not authorized to discuss the talks publicly. Coburn has balked over a requirement for private sellers to keep records of the sale of their firearms — a provision other negotiators say is essential to ensure compliance with the law. Schumer is pushing for legislation to extend background checks to gun shows and other sales where no check is required under current law.

Though the aide said the lines of communication with Coburn remain open, Schumer, Kirk and Manchin will try to get another GOP senator to sign on with the private seller provision intact.

Schumer will offer a "placeholder" bill for Thursday's Senate Judiciary Committee meeting, but Kirk and Manchin said Wednesday night they would be unable to support it.

The other measures the committee will consider include a ban on assault weapons and a bill to strengthen school safety.

Sen. Lindsey Graham, R-S.C., one of the most vocal opponents of increasing regulations on firearms, has vehemently opposed the assault weapons ban and universal background checks but said Wednesday he could be amenable to the trafficking bill, depending on the final language.

"All of us want to punish people who go out and purchase a gun through [a straw purchase]. It's already illegal. We are just trying to tighten up the law," Graham said. He noted that Iowa Sen. Chuck Grassley, the ranking Republican on the Judiciary Committee, is working with Leahy to iron out their differences on the trafficking bill.

"If Grassley and Leahy can agree, there's a pretty good chance that this thing is going to happen," he said.

Graham introduced his own bipartisan legislation Wednesday that would "clarify circumstances under which a person loses the right to receive or possess firearms based on mental illness." Sens. Mark Pryor, D-Ark., Mark Begich, D-Alaska and Jeff Flake, R-Ariz., all signed on as co-sponsors to the legislation that is also backed by the National Rifle Association. Begich, Pryor and Graham are all up for re-election in 2014.

Pryor, who has been critical of the assault weapons ban, said he would be willing to consider strengthening the law on straw purchases.

"I think we ought to enforce the laws we have on the books," Pryor said. "You kind of take that general approach, you start getting into areas like straw purchases."

Beth Levine, a spokeswoman for Grassley, confirmed her boss is in talks with Leahy, and Grassley hopes he will be able to support the bill.

On the House side, where gun measures will face an even tougher road, there appears to be some agreement on gun trafficking and straw purchases.

The House Judiciary Committee has yet to hold any hearings on the issue of gun violence, but committee Chairman Bob Goodlatte, R-Va., told reporters during a breakfast hosted by The Christian Science Monitor last week that trafficking is one of two aspects of the debate that could win approval in the Republican-controlled chamber.

"I think where we are going to find the ability to produce legislation is going to be focused on two things primarily: one is improving the background check system," Goodlatte said, though he added that expanding background checks to all gun purchases would not be part of any GOP-backed bill. "The other will be improving the efforts to crack down on illegal sales of firearms on the streets if you will, people who knowingly engage in transactions where they are selling firearms to people that should not be able to purchase them."

Rep. Scott Rigell, R-Va., one of the original co-sponsors of the House gun trafficking bill, said he wasn't surprised by the lack of pushback.

"We must have the courage when we find common ground to celebrate it and have the courage to bring it to the floor and vote for it," he said. "This bill is not capitulation. It is common sense, it is common ground."